This invention pertains to an improvement in a cartridge for removal of impurities from water. The improvement facilitates preparation of ion exchange resin, of a type capable of removal of bacteria from water, in a cartridge. This invention also pertains to a process for preparation of such a resin in a cartridge.
It is known for various adsorbing, absorbing, and filtering media including activated carbon and ion exchange resins of various types for removal of impurities from water to be packaged in disposable cartridges of a type comprising an elongated tube, water-permeable barriers disposed across each end of the elongated tube, a sealed cap having an inlet for water at one end of the elongated tube, and a sealed cap having an outlet for water at the other end. The inlet and the outlet are sealed, in shipment and storage, by removable seals. The elongated tube is charged between the respective barriers with a selected medium. Various cartridges, which are distinguished by their contents of various media, are available commercially from Illinois Water Treatment Company, Rockford, Ill. 61105, under its trademark IWT, and are described in Bulletin DX-1079 of Illinois Water Treatment Company.
As described in U.S. Pat. No. 4,199,449, it is known for large-pore macroreticular, Type 1, quaternary ammonium, anion exchange resins in various forms including chloride, sulfate, and hydroxide forms to be used to remove bacteria of various gram positive and gram negative types including E. coli, S. faecalis, and Ps. aeruginosa from water, which is to be used in manufacture of pharmaceuticals, in manufacture of cosmetics, and otherwise. Such resins are available commercially from Rohm and Haas Company, Philadelphia, Pa. 19105, under its trademark AMBERGARD, and are described in Bulletin 1E-246 (June, 1978) of Rohm and Haas Company, and in F. L. Slejko and C. R. Costin, "Upgrading the Microbiological Quality of Process Deionized Water by Ion Exchange Filtration", an undated paper (circa 1979) distributed by Rohm and Haas Company.
Before it is used, such a resin is pretreated with an aqueous solution of hydrochloric acid, which places the resin in proper ionic form, and which may sterilize the resin. However, the resin may become recontaminated with bacteria in storage, in handling of the resin, or otherwise.
A column of such a resin tends to become loaded with bacteria progressively from its inlet to its outlet. Bacteria loading a column of such a resin near its outlet tend to be washed out with water leaving the column. As bacteria from air-borne and other sources tend to be found throughout a column of such a resin unless aseptic conditions are maintained, it is known for a column of such a resin to be prepared by precolation of an aqueous solution of a suitable bactericide, as exemplified by sodium hypochlorite, through the column so as to kill bacteria found throughout the column, whereupon the aqueous solution must be rinsed from the column so as to eliminate residual contamination by the aqueous solution.
Additionally, it is known for large-pore macroreticular and other types of ion exchange resins to contain microbiocides, which may contain halogens, and which are bound either chemically or physically to the resins. Pertinent references include U.S. Pat. No. 4,076,622, which deals with large-pore macroreticular ion exchange resins, and U.S. Pat. No. 4,190,529, U.S. Pat. No. 4,187,183, U.S. Pat. No. 3,187,860 and U.S. Pat. No. 3,316,173, which deal with various other ion exchange resins. As mentioned hereinbefore, U.S. Pat. No. 4,199,449 also is pertinent here.
Also, it is known for a soluble bactericide, which may contain chlorine, to be used in various apparatus for purification of water for drinking, swimming, etc. Typically, such apparatus yield water containing some dissolved bactericide. Exemplary references include U.S. Pat. No. 4,152,262, U.S. Pat. No. 4,151,092, U.S. Pat. No. 4,115,270, and U.S. Pat. No. 2,792,942.